1. Field
The present invention relates generally to friction clutches and more particularly to an improved drive connection for the pressure plate of a friction clutch.
2. Prior Art
In friction clutches it is known to provide a drive connection for a pressure plate by means of a slot in a peripheral wall of the clutch housing which engages a radially extending drive lug on the pressure plate. Such a drive connection imparts rotary motion to the pressure plate while permitting axial movement of the plate with respect to the housing. In practice it has been found that oscillation of the pressure plate with respect to the housing results in pounding of the drive lug against the walls of the slot which in turn damages the surface of the slot such that smooth sliding motion of the lug in the slot is inhibited.
One approach to the solution of the above problem has been to select materials for the housing and pressure plate based upon surface hardness properties of the materials. This approach is subject to objection in that it limits the materials available for manufacture of the housing. The installation of inserts into the slots has been known to result in destruction of the insert. It is believed that the destruction of earlier forms of inserts is due in part to the occurrence of high velocity air currents in the clutch which displace the insert to a position in which it is subject to destructive pounding by the drive lug.